High-density wiring and high integration have progressed in printed wiring boards widely used for electronic equipment, communication apparatuses, and personal computers or the like. As a result, metal foil-clad laminates used for the printed wiring boards are required to have excellent properties such as heat resistance, low water absorbance, moisture absorption-heat resistance, and peel strength.
Conventionally, FR-4 type laminates in which epoxy resins are cured with dicyandiamide have been widely used as laminates for printed wiring boards. However, it is difficult to cope with a demand for high heat resistance by means of the FR-4 type laminates.
A technique of incorporating with a cyanate ester compound into a laminate has been known as a method for imparting heat resistance to the laminate. As the cyanate ester compound, for example, a bisphenol A-based cyanate ester compound and a novolac-based cyanate ester compound have been known (for example, see Patent Documents 1 to 3).
As one of methods for imparting water absorbance and moisture absorption-heat resistance to a laminate, a technique of incorporating a cyanate ester compound having a biphenyl skeleton to the laminate has been known (for example, see Patent Document 4).